19 February 2023

I’ve already created some org jekyll function to publish blogs for github jekyll. But there is a small issue that the org file should contains the export_html drawer with jekyll YAML metadata.

The emacs extension org2jekyll already supports extract metadata from orgmode files. So I reuse this extension with some modifications.

1. Publish settings

My orgmode files are located in <jekyll-folder>/_notes/_posts and the exported HTML files are in <jekyll-folder>/_posts:

(custom-set-variables '(org2jekyll-blog-author "kimim")
                      '(org2jekyll-source-directory (expand-file-name "~/kimi.im/_notes/_posts"))
                      '(org2jekyll-jekyll-directory (expand-file-name "~/kimi.im/_posts"))
                      '(org2jekyll-jekyll-drafts-dir "")
                      '(org2jekyll-jekyll-posts-dir "")
                        `(("post"  ;; dynamic pages like blog articles
                           :base-directory ,(org2jekyll-input-directory)
                           :base-extension "org\\|txt"
                           :publishing-directory ,(org2jekyll-output-directory)
                           :publishing-function org-html-publish-to-html
                           :headline-levels 4
                           :html-head "<link rel=\"stylesheet\" href=\"./css/style.css\" type=\"text/css\"/>"
                           :html-preamble t
                           :recursive t
                           :make-index t
                           :html-extension "html"
                           :body-only t)
                           :base-directory ,(org2jekyll-input-directory "img")
                           :base-extension "jpg\\|gif\\|png"
                           :publishing-directory ,(org2jekyll-output-directory "img")
                           :publishing-function org-publish-attachment
                           :recursive t)
                           :base-directory ,(org2jekyll-input-directory "js")
                           :base-extension "js"
                           :publishing-directory ,(org2jekyll-output-directory "js")
                           :publishing-function org-publish-attachment
                           :recursive t)
                           :base-directory ,(org2jekyll-input-directory "css")
                           :base-extension "css\\|el"
                           :publishing-directory ,(org2jekyll-output-directory "css")
                           :publishing-function org-publish-attachment
                           :recursive t)
                          ("web" :components ("images" "js" "css")))))

2. Method to create draft

;; simplify template
(setq org2jekyll-default-template-entries

(defconst org2jekyll-required-org-header-alist '((:title       . 'required)
                                                 (:categories  . 'required)
                                                 (:layout      . 'required))

;; read filename from prompt
(defun org2jekyll--read-filename ()
  "Read the file name."
  (read-string "Filename: "))

(defun org2jekyll--init-buffer-metadata (&optional ignore-plist)
  "Return an plist holding buffer metadata information collected from the user.
Any non-nil property in IGNORE-PLIST will not be collected from the user, and
will instead have its value omitted in the returned plist."
  (-concat (unless (plist-get ignore-plist :author)
         (list :author org2jekyll-blog-author))
       ;; (unless (plist-get ignore-plist :date)
       ;;   (list :date (org2jekyll-now)))
       (unless (plist-get ignore-plist :layout)
         (list :layout (org2jekyll--input-read "Layout: " org2jekyll-jekyll-layouts)))
       (unless (plist-get ignore-plist :filename)
         (list :filename (org2jekyll--read-filename)))
       (unless (plist-get ignore-plist :title)
         (list :title (org2jekyll--read-title)))
       ;; (unless (plist-get ignore-plist :description)
       ;;   (list :description (org2jekyll--read-description)))
       (unless (plist-get ignore-plist :tags)
         (list :tags (org2jekyll--read-tags)))
       (unless (plist-get ignore-plist :categories)
         (list :categories (org2jekyll--read-categories)))))

;; concat category, date string and filename
;; for example: _notes/_posts/language/2023-02-19-filename.org
(defun org2jekyll-create-draft ()
  "Prompt the user for org metadata and then create a new Jekyll blog post.
The specified title will be used as the name of the file."
  (let* ((metadata (org2jekyll--init-buffer-metadata))
     (metadata-alist (org2jekyll--plist-to-alist metadata))
     (category (plist-get metadata :categories))
     (filename (plist-get metadata :filename))
     (draft-file  (org2jekyll--draft-filename
     (add-to-file-options (org2jekyll--get-template-entries metadata-alist))
     (add-to-file-tuples (org2jekyll--alist-to-tuples add-to-file-options)))
    (unless (file-exists-p draft-file)
      (with-temp-file draft-file
        (insert (org2jekyll-default-headers-template add-to-file-tuples) "\n\n")
        (insert "* ")))
    (find-file draft-file)))

3. Publish

;; use .txt file ext as the temp file
(defun org2jekyll--publish-post-org-file-with-metadata (org-metadata org-file)
  "Publish as post with ORG-METADATA the ORG-FILE."
  (let* ((project      (-> "layout"
                           (assoc-default org-metadata)  ;; layout is the blog-project
                           (assoc org-publish-project-alist)))
         (temp-file (->> org-file
                         (replace-regexp-in-string ".org$" ".txt"))))
    (org2jekyll--publish-temp-file-then-cleanup org-file temp-file project)))

(defun org2jekyll--space-separated-values-to-yaml (str)
  "Transform a STR of space separated values entries into yaml entries."
  (concat "["
          (->> (if str str "")
               (s-split " ")
               (--filter (unless (equal it "") it))
               (--map (format  "%s" it))
               (s-join ","))

;; change org to txt, as .txt is the temp file, will be removed.
(defun org2jekyll-install-yaml-headers (original-file published-file)
  "Read ORIGINAL-FILE metadata and install yaml header to PUBLISHED-FILE.
Then delete the original-file which is intended as a temporary file.
Only for org-mode file, for other files, it's a noop.
This function is intended to be used as org-publish hook function."
  (let ((original-file-ext (file-name-extension original-file))
        (published-file-ext (file-name-extension published-file)))
    ;; original-file is the temporary file generated which will be edited with
    ;; jekyll's yaml headers

    ;; careful about extensions: "post" -> org ; page -> org2jekyll
    ;; other stuff are considered neither, so it's a noop
    (when (and (or (string= "txt" original-file-ext) (string= "org2jekyll" original-file-ext))
               (string= "html" published-file-ext))
      (let ((yaml-headers (-> original-file
        (with-temp-file published-file
          (insert-file-contents published-file)
          (goto-char (point-min))
          (insert yaml-headers))))))

(defun org2jekyll-publish-from-jekyll (org-file)
  (let* ((org-options (with-current-buffer (current-buffer) (org2jekyll-get-options-from-buffer)))
         (publish-fn (-> (plist-get org-options :layout)
                         (if 'org2jekyll-publish-post
         (final-message (funcall publish-fn org-file)))
      (org2jekyll-message final-message)

(defun org2jekyll-publish ()
  (load-theme 'kimim-light t)
  (let* ((buffer (current-buffer))
         (org-file (buffer-file-name (current-buffer)))
         (filepath (file-name-directory org-file)))
    (if (string-prefix-p (file-truename org2jekyll-source-directory)
        (org2jekyll-publish-from-jekyll org-file)
        (let* ((filename (file-name-nondirectory org-file))
               (movefile (concat
                          org2jekyll-source-directory "/"
                          (plist-get (org2jekyll-get-options-from-buffer) :categories) "/"
                          (format-time-string "%Y-%m-%d-") filename))
               (_ (rename-file buffer-file-name movefile))
               (_ (switch-to-buffer (find-file-noselect movefile))))
          (org2jekyll-publish-from-jekyll org-file)))))

4. Future plan

  • complete TAGS, CATEGORIES from existing jekyll project
  • with more and more modification, it turns out that I should fork org2jekyll now